The (COPY_TO_REGCLASS GR32:$src, VR128) pattern looks odd, but
copyPhysReg does the right thing with it. (The old pattern would
eventually produce the same cross-class copy).
llvm-svn: 160830
The SUBREG_TO_REG instruction has magic semantics asserting that the
source value was defined by an instruction that cleared the high half of
the register. Those semantics are never actually exploited for xmm
registers.
llvm-svn: 160818
These idempotent sub-register indices don't do anything --- They simply
map XMM registers to themselves. They no longer affect register classes
either since the SubRegClasses field has been removed from Target.td.
This patch replaces XMM->XMM EXTRACT_SUBREG and INSERT_SUBREG patterns
with COPY_TO_REGCLASS patterns which simply become COPY instructions.
The number of IMPLICIT_DEF instructions before register allocation is
reduced, and that is the cause of the test case changes.
llvm-svn: 160816
This is still a work in progress.
Out-of-order CPUs usually execute instructions from multiple basic
blocks simultaneously, so it is necessary to look at longer traces when
estimating the performance effects of code transformations.
The MachineTraceMetrics analysis will pick a typical trace through a
given basic block and provide performance metrics for the trace. Metrics
will include:
- Instruction count through the trace.
- Issue count per functional unit.
- Critical path length, and per-instruction 'slack'.
These metrics can be used to determine the performance limiting factor
when executing the trace, and how it will be affected by a code
transformation.
Initially, this will be used by the early if-conversion pass.
llvm-svn: 160796
hopefully make it more visible. Adjust the web-docs to have a link to
this file rather than the list itself. I described code owners as also
being gatekeepers for their part of the code, which I think is true but
isn't in the code owner explanation on the web page.
llvm-svn: 160776
It is redundant; RegisterCoalescer will do the remat if it can't eliminate
the copy. Collected instruction counts before and after this. A few extra
instructions are generated due to spilling but it is normal to see these kinds
of changes with almost any small codegen change, according to Jakob.
This also fixed rdar://11830760 where xor is expected instead of movi0.
llvm-svn: 160749
When a live range splits into multiple connected components, we would
arbitrarily assign <undef> uses to component 0. This is wrong when the
use is tied to a def that gets assigned to a different component:
%vreg69<def> = ADD8ri %vreg68<undef>, 1
The use and def must get the same virtual register.
Fix this by assigning <undef> uses to the same component as the value
defined by the instruction, if any:
%vreg69<def> = ADD8ri %vreg69<undef>, 1
This fixes PR13402. The PR has a test case which I am not including
because it is unlikely to keep exposing this behavior in the future.
llvm-svn: 160739
of an array element (rather than at the beginning of the element) and extended
into the next element, then the load from the second element was being handled
wrong due to incorrect updating of the notion of which byte to load next. This
fixes PR13442. Thanks to Chris Smowton for reporting the problem, analyzing it
and providing a fix.
llvm-svn: 160711
The long branch pass (fixed in r160601) no longer uses the global base register
to compute addresses of branch destinations, so it is not necessary to reserve
a slot on the stack.
llvm-svn: 160703
struct s {
double x1;
float x2;
};
__attribute__((regparm(3))) struct s f(int a, int b, int c);
void g(void) {
f(41, 42, 43);
}
We need to be able to represent passing the address of s to f (sret) in a
register (inreg). Turns out that all that is needed is to not mark them as
mutually incompatible.
llvm-svn: 160695
if Condition Is Met instuctions that was not correctly determining the target
instruction.
So for a jne rel32 instruction:
% cat x.s
.byte 0x0f, 0x85, 0x09, 0x00, 0x00, 0x00
% as x.s
it was incorrectly deterining the target:
% otool -q -tv a.out
a.out:
(__TEXT,__text) section
0000000000000000 jne 0xd
and with the fix it gets this correct as:
% otool -q -tv a.out
a.out:
(__TEXT,__text) section
0000000000000000 jne 0xf
rdar://11505997
llvm-svn: 160694
are targeting an ELF platform. Only fold gs-relative (and fs-relative) loads
if it is actually sensible to do so for the target platform.
This fixes PR13438.
llvm-svn: 160687
